VC625 starting and running issues

[superpro56]

Originally Posted by Shepard

Does the valve cover have any kind of a valve system [PCV Valve] built into the inside? Few the pulse line is hooked into the PCV control you will have a weaker pulse signal. If you read this it may better explain.


https://affordablegokarts.com/pages/fuel-pump-setup

That was my thought as well, and it could be a combination of bad/weak signal and/or a pump that simply can't keep up. I would go with a different pump that is proven on these engines. Mine has run well for 2 years with this exact pump.

https://www.eccarburetors.com/walbro...tyle-fuel-pump

While you're at it get an adjustable main jet.

http://www.nrracing.com/product-p/99101-zh8-ajust.htm

At least you have a fighting chance with these two items.

[lx5spd]

Originally Posted by Shepard

Does the valve cover have any kind of a valve system [PCV Valve] built into the inside? Few the pulse line is hooked into the PCV control you will have a weaker pulse signal. If you read this it may better explain.


https://affordablegokarts.com/pages/fuel-pump-setup

There is no CCV on the valve cover. Just the oil fill cap and the pulse fitting.

Originally Posted by superpro56

That was my thought as well, and it could be a combination of bad/weak signal and/or a pump that simply can't keep up. I would go with a different pump that is proven on these engines. Mine has run well for 2 years with this exact pump.

https://www.eccarburetors.com/walbro...tyle-fuel-pump

While you're at it get an adjustable main jet.

http://www.nrracing.com/product-p/99101-zh8-ajust.htm

At least you have a fighting chance with these two items.

Fuel pump is Out of Stock :(

n00b question, but which main jet do I need for this carb? Their options are GX200 & 6.5 Ru*ing or GX390 & 420 Predators.

Also, from my understanding, removing the factory main jet on this carb requires some “surgery”. Is there a complete carb that I can purchase somewhere that will work this engine and has the adjustability that I need?

[lx5spd]

I just tried a spare fuel pump my buddy had for his G9 cart. Same issue with low fuel level in the filter housing. 3 different pumps and same result, so I don’t think it’s a pump issue.

[superpro56]

The main jet can be accessed by removing the float bowl on the bottom of the carb. Main jet is on the underside of the main carb body and can be removed with a flat blade screw driver. Can be drilled just like the idle jet.

Im thinking the pulse is weak. The best course I think at this point is to find an electric pump and try that. You will almost certainly need a return line with that setup.

[lx5spd]

I can do that.

Can anyone recommend an electric fuel pump for me?

[raydhd]

Holley mighty mite 12-426 Using one on sled powered harley cart. Works great. Actually have one to put on my VC 460 IF the B&S pump stops working but it also continues to work great.

[lx5spd]

Just an update:

I replaced the OE fuel pump with the recommended Walbro unit and it cleared it right up. She still stumbles right before the red line, which I’m guessing is a carb tune issue. I can live with it since it comes on at like 3800 RPM and the limiter kicks on at 4000 RPM.

Buy holy hell this thing gets out of the hole. I’m going to need the 8:1 gears, because it gets to the limiter instantaneously. Off a brake stand it’ll pull the front wheels about 6”.

[superpro56]

Glad you got it sorted, sounds like a fun ride!

[1badmustanglx]

Did you drill anything out on the carb or just replaced the fuel pump with the walbro? Im having the same issues, idles fine, after a hard start.